Metalized paper electrical condenser



Oct. 30, 1945, 'R. A. GROUSE ETAL METALLIZED PAPER ELECTRICAL CONDENSER Filed July 1, 1945 2 Sheets-She et 1 Inv ant QIS Riiuta. 61 min:

' James R gers Faker u Oct. 30, 1945. R. A. GROUSE EIAL 2,388,139

METALLIZED PAPER ELECTRICAL CONDENSER Filed July 1, 1945 2 Sheets-Shet 2 g Richagg fi Grouse I dame; Rogeng rnemd Oct. so, 1945 METALIZED PAPER ELECTRICAL CONDENSER Richard Alfred'Grouse and James Rogers. London, England. auignors to A. ll. Hunt Limited, London, England, a British company Application July 1, 1943. Serial No. 493,172 In Great Britain July 13, 1942 4 Claims.

sess a high capacity for a given size, as compared with condensers built from separate sheets of metal and paper.

The present invention relates more particularpaper condensers wherein the metalized strips of paper are wound and assembled to form con-v denser units. The invention comprises a method of winding the strips and means for turning over the metalized edges of the same during the winding operation.

According to the present invention, strips of metalized paper each having an unmetalized margin along one edge, are taken and are wound together into a. single roll with the unmetalized edges of the strips of adjacent layers'lying alternately to one side and to the other side of the roll, the metalized edges of the strips being arranged to overlap the unmetalized margins of the adjacent strips and to project beyond them so as to afford an easy means of eflecting metallic connection to each pole of the condenser.

Conveniently the strips are fed from rolls. It is possible to employ an even number of rolls, but conveniently there are two rolls, one for one pole and the other for the other of the condenser and the paper of one roll is of the opposite "hand" to the paper in the other, that is to say the unmetalizedmargin is upon the opposite side of the strip. I

An important feature of the present invention lies in the fact that the metalized edges of the paper are turned over outwardly in the wound condenser so that the paper is of double thickness at the exposed edge and the metalized surface of the paper makes metallic contact from layer to layer throughout the edges oi'the condenser. Further the metalized surface is thereb exposed at the ends of the condenser which facilitates making electrical connection to the metalized layers. This construction much reduces the internal resistance and inductance of the condenser.

The invention includes a special means of effectins the turning over of the edge and the process or turning it over by the aid of such means as hereinafter described. The invention further includes condensers when wound by a process of the present invention.

1m 1y to that step in the construction of metalized By way of example one form of'apparatus for carrying the invention into effect and of the process as carried out therein will now be de-' scribed with reference to the accompanying drawings, in which:

Figure l is a side elevation of the apparatus;

Figure 2 is a cross section upon the line 22 of Figure 1 looking in the direction of the arrows;

Figures 3, 4 and 5 are details of the edge turning operation and of the means used therefor;

Figure 6- is a diagrammatic section through some of the layers of the condenser, and

Figure 7 is a view of a completed condenser in accordance with the invention.

Referring to Figures 1 and 2, on a base-plate ii there is provided an upstanding wall i2 which carries the working parts. The wall i2 has vertical slots i 3, H in which are mounted brackets l5, l6 respectively, the brackets being secured in place in the slots by means of stems which pass through the slots and are tightened in place by nuts I! at the back of the wall l2. The brackets may be adjusted up or down to any desired position by slackening the nuts i1 and then sliding the brackets along the slots.

The brackets I! in the slot l3 serve to support feed rolls It on which are wound metalized paper strips i9, 20. The feed rolls l8 are supported on the points of hardened, conically pointed, screws 2|, 22 which pass through arms 23, 24 on the brackets i5 and which can be locked in any desired position of adjustment by means of locknuts 25. The paper strips I 9 are kept from moving axially relativel to the feed rolls it by means of brass flanges 2B, 21 having bosses 28, 29 which slide on the ends of the feed rolls I8 and are secured in place by screws 30. By adjusting the screws 2|, 22 the upper feed roll carrying the strip is may be set over to one sideand the lower feed roll carrying the strip 20 may be set over to the other side of the centre line between the bracket arms 23, 24 in the manner shown in Figure 2 of the drawings, and this is necessary for proper cooperation with the edge-tuming devices (which are mounted in the next slot l4) The edge-turning brackets it are similar to the brackets IS on which the feed rolls l8 are mounted but their depending arms Si, 32 instead of supporting a feed roll such as It, support a roller 32 (Figure 3) which constitutes a foldcreasing member. The roller 33 has a flange 34 her already described for the screws Ii. 22 and the brackets II. The edgeguide 90 on the upper of the two brackets it mounted on that end of the roller a which comes'close to the wall it, while the edge-turning guide 3| on the lower bracket is is mounted at the other end or its fold-creasing roller.

Between the brackets ll, II and at a somewhat higher level than that of the normal position of adjustment of the rollers i8 and 83 there are rollers 40, ll which are mounted on spindles projecting from the wall i2 and constitute tension bars over which the paper strips IO and 20 respectively are drawn in the course of the winding operations. The strip it passes over the tension bar 40 and thence downwardly to the underside of the upper roller 33, in so doing passing b the edge-turning guide 34 and being engaged along its metalized margin by this guide. The lower strip 20 in a similar way passes over the tension bar it and downwardly to the lower roller 33, engaging the edge-turning guide 35 with its D- posite edge to the edge of the strip is which enases the guide 34. 7

From the edge-turning devices on the brackets ii the strips pass to a wind-up spindle 42 which may be driven by a belt on a pulley II from an electric motor, not shown. The spindle l2 carries flanges N which are set at an appropriate distance apart and the two strips i9, Iii are wound up together on the spindle 42. When enough of the paper has been wound up to constitute a condenser of the desired capacity it, and the side flanges M, are slid endwise oil the spindle l2. Thereafter a further condenser can be wound by starting the ends of the metalized strips again on the spindle l2 and recommencing its rotation.

Any desired means may be provided, if necessary. in addition to the tension bars 40, ll for producing a certain amount of endwise tension in the strips i9, 20 as they are being wound up. For example there may be a brake drum or brake disc, either electrical or mechanical, on the feed rollers ",1: desired.

In the operation of this apparatus a roll of metalized paper It, having an unmetalized margin along one edge, is mounted in the upper bracket i and another roll of metalized paper, having an unmetalized margin along the other edge, is mounted in the lower bracket it. In the disposition of the parts which is shown in the drawings it is assumed that the unmetalized margin of the upper strip is is on the left as viewed in Figure 2 and the unmetalized margin of the strip 20 is on the right. The strip i9 passes over the tension bar 10 and under the fold-creasing roller 33 and thence to the wind-up spindle 42. As viewed in Figure 3, the strip is has its unmetalized margin on the right and is proceeding away from the observer toward the wind-up spindle 42.

The endwise position of adjustment of the feed roller is is made such that the metalized edge of the strip is comes into engagement with the edge-turning guide 34- which is formed as a flange on one end of the roller 33,. As the paper passes beneath the roller it causes the roller to rotate and the flange 34 turns with the roller in the direction indicated by the arrow in Figure 3. The result is that the edge of the paper strip is bent over, as indicated at iii in Figure 3. Figure 4 is a detailed section through the parts looking in the direction of travel or the paper at the point 50 of Figure 3, and it shows how a narrow margin of the edge of the paper is turned up at essence right angles. As this turned-up portion approaches the roller 83 it is made in told over as indicated at bi and in being bent to pass round the roller 88 it is creased down flat as shown at I! in Figure a. Thenceiorward the paper strip proceeds toward the wind-up spindle 42 with its metalized edge doubled over along the margin, the metalized portion being on the outside of the bend. It will be understood that the metalized surface extends across nearly the whole width of the strip and only the edge of the metalized portion is bent over in this way and by careful adlustment it is possible to make the width of the folded-over portion very narrow, much narrower than is shown in the drawings, Figures 3 to 6. Indeed the bent over metalized portion may not be in practice more than one thirty-second of an inch wide, and it is possible to maintain such a narrow folded-over edge with perfect uniformity through the operation of unwinding a strip from the roll on the bracket i5.

The strip 20 on the lower roll has its edge folded over in exactly a similar way but it is arranged with the metalized edge running along the opposite margin and the edge-turning strip 35 is therefore located at the opposite end of the roller, that is to say the nearer end as viewed in Figure 1.

The two strips are not precisely vertical over one another as they come away from the rollers 33 but are so secured that they tend to wind up, on the spindle $2, in the manner indicated diagrammatically in Figure 6. where alternate layers of the 'strips l8 and 20 are shown wound together so that they are intercalated with one another. The resultant wound condenser is shown in perspective in Figure 7 with the bent over metalized edges indicated at 52. and the two strips It and 20 are clearly seen.

It will be observed that the turned-over portions 52 of the metalized edges of the strips present a metalized surface to make electrical contact with the metalized portion of the next layer of the winding. Moreover they exactly fill up the spaces which would otherwise be left at the ends of the condenser where the overlappin strips project beyond one another. The end portions of the condenser are therefore in electrical contact with one another over the whole radial width from the centre to the outside of the Winding. These end portions serve to provide a convenient place for making electrical connection to the metalized surfaces with a minimum of trouble, electrical resistance and tendency to inductive oss.

In order to facilitate the making of the electrical connections a mask is put over the end of the wound condenser and hot molten metal is sprayed on to the metalized end portion through the apertures in the mask so as to form a cruciform area 53 of sprayed metal. To this sprayed-on metal terminal wires II are secured by soldering and are then twisted together as shown in the drawings.

It is convenient in winding the condenser, if it is to retain its circular shape after having been wound, to flt a cardboard tube 58 on the wind-up spindle l2 and this tube will remain in situ after the condenser-has been removed from the apparatus. The completed condenser may be protected by any desired form of easing.

We claim:

1. Apparatus for winding paper condensers comprising in combination supporting means for holding a pair of rolls of metalized paper strip on parallel axes in slightly staggered relationship so that one edge of each strip overlaps the corresponding edge of the other strip, a winding spindle parallel to the axes of the rolls and in proper alignment to receive strip unwound from the rolls, means for driving the winding spindle, foldcreasing rollers located between the winding spindle and each roll-supporting means in such position that each of the strips coming from the rollsupporting means follows a bent course around its fold-creasing roller, an edge-turning guide located in advance of each fold-creasing roller so as to engage that edge of the paper strip passing over the roller which overlaps the corresponding edge of the other strip of the pair and turns up the edge preparatory to it being folded down by passing around the fold-creasing roller, and means for keeping the strips and the edge-turning guides in strict lateral alignment relatively to one another, whereby opposed narrow edges, one on each strip, and each of less width than the overlap, are folded over to occupy the spaces left I by the overlap between successive turns of paper of the wound condenser.

2. Apparatus as claimed in claim 1 wherein each edge-turning guide consists of a flange upon the corresponding fold-creasing roller.

3. Apparatus as claimed in claim 1 wherein each edge-turning guide consists of a flange upon the corresponding fold-creasing roller and a tensiOn bar is located between the supporting means for each roll of metalized paper strip and the edge-turning guide therefor in such a position RICHARD ALFRED GROUSE. JAMES ROGERS. 

